Method of felting sheet material



Dec. 14, 1943. c. G. MUENCH METHOD OF FELTING SHEET MATERIAL 5 Sheets-Sheet 1 Filed 001;. 18. 1959 A ORNEY.

Dec. 14, 1943. c. e. MUENCH METHOD OF FELTING SHEET MATERIAL 5 Sheets-Sheet 2 Filed "Oct. 18, 1939 ATTORNEY.

C. G. MUENCH METHOD O FELTING SHEET MATERIAL Filed Oct. 18, 1939 5 Sheets-Sheet 3 llllll C. G. MUENCH METHOD OF FELTING SHEET MATERIAL Filed Oct. 18, 1959 5 Sheets-Sheet 4 IN VENTOR.

ATTORNEY. v

Dec. 14, 1943. c. s. MUENCH METHOD'OF FELTING swam MATERIAL Filed Oct. 18, 1939 5 Sheets-Sheet 5 INVENTOR. 04/7?! 61?. Mac-372C 72 BY W ATTORNEY.

Patented Dec. 14. 1943 METHOD OF FELTING SHEET MATERIAL Carl G. Muench, New Orleans, La., assignor to The Celotex Corporation, Chicago, 111., a corporation of Delaware Application October 18, 1939, Serial No. 300,045

(CL 92-39) This invention relates to a method of felting 2 Claims.

fibrous sheet material and more particularly relates to a tamping device on a Fourdrinier machine adapted for producing a denser and more compact surface finish by-causing the fines of the felted fiber to arise to the surface of the felted fiber sheet. A Fourdrinier machine to which this tamping device is applicable comprises essentially a felting screen, pressing rolls and felts, suction boxes, and a head box and a machine box from which the stock fiows to felt on the screen. g

The method herein described for tamping the felted fiber sheet is effected by reciprocating tampers vertically with respect to the thickness of the sheet as it is felted, preferably at the suction boxes of the Fourdrinier machine, So that as the Water from which the fiber is felted is filtered from the sheet, the felted fibers which are sometimes formed into lumps are tamped to cause removal of the lumps to form a smooth surfaced sheet and also to cause the fines of the felted fiber to come to the surface to form an excellent surface finish and also a denser and more uniform board. This method of tamping also utilizes means for varying the pressure applied to the tampers whereby the density of the finished felted board may be regulated and controlled. The density and also the surface finish may also be controlled by the relative longitudinal posi- Foam which is deposited on the surface of the felted sheet forms, however, is a disadvantage where it is desired to have the finished surface as that surface which is felted and pressed under v the felts of the Fourdrinier machine or to have of dissipating the foam .and causing the fibers to mix up in the stock that the novel skimming apparatus is used in conjunction with the use of the tamping apparatus to provide an excellent surface finish and a,denser board than is usual with the Fourdrinier machine.-

' The skimming device which is disclosed and claimed in the co-pendlng application of Carl C. Muench Serial No. 300,046, filed October 18, 1939, and Which is a continuation-in-part of this application, primarily consists of a conveyor having slats mounted thereon with a portion of the conveyor extending longitudinally with respect to the Fourdrinier machine and at an angle to the felting screen so that the slats dip slightly below the level of the pond; and, as the slats move in a direction opposite to the flow of the liquid in the pond they serve to dissipate the foam and cause the floating fibers and the occluded fibers in the tion of the tampers with respect to the suction I boxes.

It is also preferred to use this method of tamping in conjunction with the method for dissipat- I ing the foam which forms on the stock pond of a Fourdrinier machine and mixing the floating fibers and those floated by thefoam back into the stock wherein the method of dissipating the foam and mixing the fibers is to skim the surface of the pond in a direction opposite to the fiow of the stock in the pond formed at the machine chest. The foam which forms and rises on the surface of the pond is apparently caused by the agitation of the stock whereby sizing which is admixed with the stock of liquid and fiber and is ordinarily a rosin size causes the formation of foam which risesto the surface of the pond and with which there is always some content of fine fibers floated thereby. This foam, if allowed to be felted out on the finished sheet, would be deposited on the surface and would leave stains and fine fiber on the finished surface necessitating an additional operation of sanding or the equivalent to provide a clean finished surface on the finished material.

foam to be mixed with the stock in the pond.

The novel tamping device primarily consists of multiple tampers moving vertically with respect to the felted sheet preferably above the suction boxes of the Fourdrinier machine. The tamping device is a self-contained unit wherein tampers located on opposite sides of their driving means are reciprocated through the oscillatory movement of the driving means causing the tampers to move in opposite directions with respect to each other. The tamping device is provided with means for longitudinally adjusting the tampers with respect to the suction boxes and also with means for vertically adjusting the tampers with respect to the thickness of the felted fiber sheet. The tamper also is provided with adjustments for regulating the pressure applied to the tampers in order to adjust the density and surface finish of the felted fibrous sheet.

It is therefore a principal object of the invention to form a sheet form material in board form having a smooth and uniform surface and whereinthe finished board is stronger and more uniform throughout and may be considered as having a more dense surface and of greater density than is usual in the case of felted fiber boards formed on a Fourdrinier machine.

Another object of the invention is to provide a method of tamping the surface of a sheet of fibrous material as it is felted from a water suspension of fiber to remove the lumps of fibers and to cause the fines of the felted fiber sheet, to arise to the surface making the surface of the to rise to the surface of the Fourdrinier pond and to stain the finished surface of the felted sheet are formed, they are caused to be dissipated while at the same time as the sheet is, continuously felted, the surface is so tamped as to bring the finer particles to the surface forming a finished sheet of greater density and the finished surface more compacted by the rising of the fines of the felted fiber to the surface of the finished sheet.

Another object of the invention is to provide an excellent surface finish for felted fiber boards, and therefor a tamping device is used in conjunction with the Fourdrinier machine head chest agitator which causes the fibers to be-uniformly felted whereby the tamping device brings the fines within the felted fiber sheet to the surface of the sheet so that an excellent surface finish is hadfor the finished felted fibrous board without the additional necessity of sanding the finished sheet. v

A principal feature of the invention is the provision of a tamping apparatus comprising vertically moving tampers positionedjon the Fourdrinier machine where the suction boxes are located so that as the water from which the sheet is felted is removed, ordrains away, the felted surface of the sheet is'tamped to increase the density and strength of the finished sheet and to provide an excellent finished surface for the sheet by causing the fines of the felted fiber sheet to rise to the surface of the sheet.

Another feature of the invention is that of providing the tamping device with horizontal adjustments wherein the position of the tampers may be adjusted with respect to the suction boxes whereby the density and surface finish of the finished board may be regulated.

Another feature of'the invention is that of providing the tamping apparatus with vertical adjustments whereby the relative position of the tampers with respect to the thickness of the felted board may be adjusted as well as the variation of the tamping effect.

Another feature of the invention is to provide means for adjusting the amount of force applied to the'tampers whereby the resulting density and surface finish of the board is regulated.

Further objects and advantages will become apparent from the following detailed description of the preferred embodiment of the invention as illustrated in the accompanying drawings, wherein like reference characters indicate similar parts. a

Referring to the drawings:

Figure 1 is a schematic view illustrating in side side elevation the relative position of a tamping 'device with respect to the suction boxes, the felt and breast roll of a Fourdrinier machine and alsoillustrates the relative position with respect to a skimming device which is located adjacent the breast roll and the pond from which the fibrous sheet is felted; a

Figure 2 is a side elevation of the tamper illustrating means for horizontally and vertically adjusting the tamper with respect to the suction boxes of the Fourdrinier machine;

Figure 3 is a plan view of the tamper;

Figure 4 is a side elevation partly in section of the tamper illustrating a means for actuating the tampers;

Figure 5 is an end elevation of the tamper, showing partly in section the framework and deckles of the Fourdrinier machine;

Figure 6 is a side elevation in section along line 6--6 of Figure 5 looking in the direction of the arrows, illustrating the details of the mechanism for horizontally and vertically adjusting the tamper; and,

Figure '7 is an enlarged vertical sectional view of the operating mechanism for vertically adjusting the tamper.

Referring to Figures 1 and 2 of the drawings, the numeral I0 indicates the structural framework of the Fourdrinier machine which has mounted thereon a tamping device H. The tamping device II is preferably supported'by the framework I2 overlying suction boxes I3 of the Fourdrinier machine. The framework l2 preferably comprises vertical supports it to which are secured laterally spaced longitudinally inclined supporting member l5, Figures 1, 2, 3 and 4.

The tamper ll comprises a main supporting frame 16 which is adapted for longitudinal movement with respect to the inclined supporting members l5. It is preferred to construct the main frame l6 .with'supporting members I! laterally spaced and adapted for longitudinal movement on the inclined supporting members [5.

I Secured to the supporting members I! are vertistructural channel members placed backto back with spacers .20 therebetween. Positioned below the frame member i9. and secured to the uprights l8 are longitudinally spaced ears 2| which are preferably formed from structural channel pieces and welded to the uprights l8. For spacing and stiffening the main frame It, spacing pipes 22 and 23, Figures 3 and 4, extend transversely between the longitudinal frame members I9 and the ears 2| respectively. Tie rods 24 extending through the spacing pipes22 and 23 and suitably secured at each end serve to complete the main frame iii of the tamping device. Although it has been preferred to stiffen the main frame by the "use of tie rods and spacing members, it is obvious that any other suitable mechanical equivalent may be utilizedfor strengthening the framework IS.

The framework 25 is mounted for vertical adjustment on the uprights l8 and transversely spaced across the main frame 16, as best illustrated in Figures 3 and 5, for supporting a tamping drive mechanism 28 and its associated tampers 21 which form means for continuously tamping the felted fibrous sheet, whereby a felted sheet is formed which is homogeneous throughout. The 'framework 25 comprises preferably end frame members 28 comprising spaced channel members 29, Figure 7, secured to transversely extending main frame channel members 30 longitudinally spaced, as illustrated in Figure 4. The main frame members 30 ;are bracedand spaced bybearing supporting members 3|, for an operating shaft 32, and bearing supporting members 33 for an adjusting rod or shaft 34., In order to provide guides for the uprights l8, Figures 5, 6 and 7. Angle shaped guide members 31, Figures 2, 4, 5, 6 and '7, are preferably riveted to the flange portion 35 of the channels 30 to allow the main frame 25 to be vertically guided by the uprights I8 withinthe spaced guide members 31. p

The tamping mechanism 26 for actuating the tampers 21 ispreferably supported, Figures 2, 3, 4 and 5, on a platform 38 welded or otherwise secured to the main frame channel members 30..

ning over the belt pulleys 48 and 49, respectively,

connected to the motor 42 and jack shaft 43.

The main operating shaft 32 is given an oscillatory motion by means of an eccentric drive 50 on the end of the jack shaft or ,crank shaft 43 which with its associated members forms means for actuating the oscillatory shaft 32. The eccentric drive mechanism 56 comprises'an eccentric disc secured to the shaft 43 and split eccentric straps 52 and 52'. For counterbalance ing, the eccentric counterbalances 53 may be.

secured to the shaft. The eccentric disc 5| is journaled within the eccentric straps 52 and 52' and the eccentric strap 52' isadjustably secured to a connecting rod 54. The connecting rod 54 is adjustably connected to a clevis 55 at the other end of the rod to provide an adjustment to raise one set of tampers 21 with respect to the other set of tampers, Figure 4. A crank arm 56 is keyed to one end of the operating shaft 32. The crank arm 56 is provided with adjusting holes 51 to which the connecting rod clevis 55 may be adjustably connected to vary the length of stroke of the tampers 21. The aforesaid structure and associated members form actuating means for the tamping means.

The main operating shaft 32 which is journaled'in bearings 58 is transversely mounted on the main frame 25 and is supported at one end of theshaft 32 by the platform 38 and by the bearing supports 3| intermediate the length of the shaft and at the opposite end thereof. Rocker arms 59 are keyed and transversely spaced along the shaft 32 as illustrated in Figures 3 and 5. The rocker arms 59 serve to give a vertical reciprocatory motion to the longitudinally spaced sets of tampers 21, Figure 4. The'rocker arms at each end thereof have pivotally mounted thereon clevises 60 to which are adjustably secured tamper rods -6| by adjusting stud bolts 62. The tamper rods 6| are guided by rod guides 63 by longitudinally spaced holes 64 formed therein. The rod guides 63 are supported beneath the main frame channels by supports 65 welded or otherwise secured thereto, Figures 4 and 5. It

is therefore obvious that the rod guides 63 maintain the tampers 21 longitudinally spaced apart as they are reciprocated vertically by the rocker aluminum or brass or the like material which will resist corrosion and are preferably U-shaped in section as illustrated in Figure 4. It is obvi ,ous, however, that these tampingbars' may be formed of wood without departing from the scope of the invention.' The tamping bars have even been formed of wire screen, but it is to be understood that whatever material they are formed of the bars 66 should be so placed as to allow for the ready escape of the occluded air in the fibrous sheet. The tamping bars 66 are secured to fingers 61 and 68, respectively, by riveting or other suitable fastening means and are clamped together as best illustrated in Figure 4. i

The fingers 61 are adjustably secured to the tamper rods 6| at their lower ends by the adjusting stud bolts 62. A particular feature of this adjustment is the provision for leveling the tampers 21 transversely with respect to the Fourdrinier machine.

In the operation of the tamping mechanism 26 the motor 42 is preferably operated at a speed of substantially 900 R. P. M. and with a reduction of substantially two to one the eccentric is actuated at substantially 450 R. P. M. As the eccentric is actuated at 450 R. P. M. the operating shaft v 32 is therefore actuated also at 450 R. P. M. thus reciprocating eachof the tampers 21 respectively in alternate directions at, 450

strokes per minute whichthoroughly tamps the felted fiber sheet causing a sheet to be formed of uniform character throughout with the ex-.

ception that the finer fibers in the sheet are caused to arise to the surface forming a sheet which has a fine textured surface and a denser and harder surface than that formed on the opposite untamped side of the felted sheet. The tampers have also been operated at 225 strokes per minute but the higher rate is more desirable in the effect produced. It is therefore preferred to operate the tampers within the range of from substantially 225to 450 strokes per minute.

For adjusting, the main frame 25 vertically with respect to the sheet as it is being felted, there is provided an adjusting mechanism 69 on each side of the tamping device so that an operator from either side of the Fourdrinier machine may adjust the tampers 21 vertically in accordance with the thickness of the sheet being formed. The adjusting mechanism 69 comprises hand wheels 10 secured to the adjusting shaft 34 which because of its length is coupled together at the center by a coupling 1| to take care of any variation inalignment of the shaft 341 from either end of the machine. The shaft 34 is suitably journaled in bearings 12 mounted on supporting members 33, Figures 2, 3, 6 and 7.

-Worms 13 are keyed or otherwise secured to the shaft 34 adjacent each end thereof and in turn actuate worm wheels 14 mounted for vertical movement on threaded adjusting rods 15 suitably secured in upper supports 16 and lower supports 11 mounted on the longitudinal frame members l9 and supporting members l1, respectively, of the main supporting frame l6. Guide members 18 are mounted at each end of the main frame 25 for supporting the main frame on the worm wheels 14. The guide members 18 are prefera-bly mounted between the channel members 29 of the end frame members 28 and are in en-- gagement with the worm wheels 14 and guided on the adjusting rods 15 so that as the hand wheels 10 are turned, .the main frame 25 for supporting the tampers 21 is vertically adjusted up or down with respect to the sheet being felted depending upon thedirection in which the hand wheels I8 are rotated. It is obvious that other mechanical equivalents for the simple adjusting mechanism for*raising and lowering the main frame 25 may be utilized.

A clamping device 80 is mounted at' each end of the tamping apparatus to prevent movement of the main frame 25 with respect to the main supporting frame I6 as the tamping mechanism is actuated. The clamping device comprises preferably an adjusting member BI, Figures and 6, in threaded engagement with a nut 82 with the adjusting member 8| adapted to move vertically in an adjusting slot 83 in the forward vertical uprights I8. In order to adjust the tampers 21 vertically with respect to the Fourdrinier machine,

junction with the skimming apparatus. The supporting members II are preferably cast with the thrust members 9| cored therein or it is obvious that the members Il may be formed from structural steel members suitably welded or otherwise secured.

the clamping device 80 at each end of the tamper has been provided for vertically adjusting and When the tampers 21 are suitably It is also preferred to form supporting members I! so that a guide 93 is formed therein complementary to the upper surface of the inclined supporting members I5. A clamp 94, Figures 5 and 7,

is provided to maintain the supporting members- 96 oneach supporting member I'I determines the relative position of the main frame I6 of the tamping apparatus II with respect, to the supporting frame I2 therefor as the tamping aplocking the-supporting frame 25 for the tampers I in its adjusted vertical position.

Although the preferred mechanism has been described, it is obviousto one skilled in the art that variations thereof maybe utilized without departing from the scope of the invention as dis.- closed and claimed.

In order to adjust the tamping apparatus II longitudinally with respect to the suctlon'boxes I3 and the suction box cover 84 of the Fourdrinier machine, an adjusting mechanism 85 is provided at the forward end of each side of the framework I2 for supporting the tamping apparatus I I. The adlusting'mechanism 85, as it is similarly constructed on each side of the tamping mechanism, will only be described with reference only to the left side of the Fourdrinier machine as one stands facing in the direction of travel of the finished felted sheet as it is formed on th Fourdriniermachine, Figure 2.

Referring to Figures 2, 3, 6 and 7, the adjust- 21 longitudinally with respect to the pond and means 99, and this mechanism for driving thedeckles which is well known in the art has not been illustrated as it is not necessary for the understanding of this invention.

v The tamping apparatus II as illustrated diagrammatically in Figure 1 may also be used in suction boxes and comprises preferably a hand wheel 88 secured to. an inclined, adjusting rod 81 which is journaled in bearings 88 secured at each end of the inclined supporting member I5. A .collar 89 at the end ofthe adjusting rod 81 takes up the thrust of the adjusting rod and also in conjunction with the end of the threaded rod prevents movement of the adjusting rod longitudinally. As the hand .wheel 86 is turned inelther direction, a nut 80, Figure 6, which is in abutting relationship between thrust members 9| located tamping apparatus II is adjusted longitudinally in either direction with respect to-the suction boxes I3 and their associated suction box covers 84 and also with respect to the skimming apparatus 82. if the tamping apparatus is used in conconjunction with the skimming apparatus 82, and the skimming apparatus and its method of operation have been disclosed and claimed in the 'copending application hereinbefore identifled. The skimming apparatus 92 and its associated members form means for dissipating and skimming the foam which is formed and comprises preferably transverse flights IIIII which also operate between the inner flights of the deckles -91 and are secured to conveyor chains IIII so driven that the lower flight I02 moves in the direction of the arrow I03, which direction as indicated by the arrow I83 isopposite to the flow of the liquid in the pond formed at the machine box of theFourdrinier machine. The conveyor chains IOI are suitably driven through the sprocket and chain driven mechanism I04 from the shaft of an agitator I85. The preferred range of linear speed of the skim ming apparatus is such that the flights I00 move substantially at the rate of from 250 inches to 425 inches per minute although it may be even uperated at a slower speed. The agitator I05 which is preferably operated at. 30 R. P. M. and within the range of from substantially 30 to 50 R. P. M. is preferably inthe form of a double spiral formed from spirals of opposite hands, and skimming apparatus 94 are suitably driven through sprocket faster, and upon which is felted the fiber discharged from the head box I08.

Having thus disclosed in detail the novel tamping apparatus and the skimming apparatus with which it is preferred to use the tamping an Figure 1.

paratus, the method of operation will be described in connection with the felting of a fibrous sheet, utilizing the skimming apparatus to dissipate the foam and floating fibers and the tamping apparatus to produce a felted sheet having a fine textured surface thereon but otherwise of uniform characteristics throughout.

In the operation of the Fourdrinier for felt.- ing fiber insulation board'and the like using the novel skimming device and tamping apparatus, it is preferred to use the tamping device I I either alone or in conjunction with the skimming apparatus 92. This is illustrated schematically in The tamping device ispreferably positioned between the skimming device and the first felt 99 of the Fourdrinier machine and over the suction boxes I3, and their associated cover 84. The tamping apparatus may be adjustei longitudinally with respect to the Fourdrinier machine so that the tampers 21 may be reciprocated either within the pond level or outside thereof.

- It is also possible to adjust the level of the pond so that the tampers 21 may or may not operate therein. The level of the pond and the position of the tampers primarily determined by the freeness of the stock being felted.

The stock, as it comes from the head box I09 into the machine chest where it forms a pond, reaches a predetermined level as indicated at H0. The stock may comprise ligno-cellulose fiber, preferably bagasse fiber, which has been given a light digestion and then subjected to a suitable refining in a Clafiin or Jordan or other refiner to reduce the fiber to a suitable fineness,

and which, when it is in water suspension, will form a stock having a predetermined freeness.

This refined fiber may have admixed therewith the surface tension whereby the action of the agitator I05 causes bubbles to form in the stock and which in rising to the surface float to the surface particles of dirt and fine fibers to form on the surface of the pond a foam having therein such dirt particles and fine fibers floated from the stock. It has been found, however, that by dip into the surface below the pond level to a fiow of the liquid in the'pond to bring and to keep the foam within the sphere of action of the spiral agitator I05 whereby the foam is dissipated and any particles or fine fiber which were may also be added suitable substances and/or certain treatments for fireproofing or suitable toxic treatments for fungus and insect-proofing the finished felted fiber board.

Although this invention has been described in connection with felting of bagasse fiber, the novel skimming device and tamping apparatus and method of operation thereof are equally adaptable in connection with the formation of sheets made from ground wood or any other suitable fiber. The pond is preferably agitated by the spiral agitator I05 to maintain the stock at uniface malnng it necessary to sand the finished sheet or otherwise process the surface to remove the stains and irregularities. If felted into a sheet, in connection with the manufacture of which embossing rolls are used in conjunction with the felting operation to emboss a design on stains on the embossed surface which could not be readily removed; and thus, there would not be produced on the sheet a finished surface pleasing to the eye.

The stains which arise from a deposit of the foam on the surface of the sheet are produced due to the efiect of the rosin size in decreasing the surface of the sheet, there would be formed carried thereby are released and by the action of the agitator again admixed throughout the stock in the pond.

As the fibers are felted on the wire I08, the fibrous sheet, which has not been indicated in the drawings as it is not believed necessary for an understanding of the invention, travels forwardly over the suction boxes I3 and their assopoint it is preferredto use the tamping device II, illustrated diagrammatically in Figure 1, to

tamp the surface of the felted sheet to cause the finer fibers in the sheet toarise to the surface and to thus form asheet which has'a fine textured surface and a denser and harder surface than that formed on the opposite untamped side of the felted sheet. The tampers 21 which provide this tamping action preferably comprise a plurality of tamping bars 66.- It is preferred j to actuate the tampers 21 by a vertical reciprocatory motion at a rate of substantially 225 strokes per minute for each set of tamper bars. The tamper bars-as they are thus reciprocated, as'the sheet of felted fiber is being formed and conveyed thereunder, cause a sheet of greater density to be formed and particularly the surface thereof yvhich is being tamped is of a greater density than the opposite untamped surface. This tamping also produces a fine textured surface by bringing the finer fibers in the sheet to the surface. The amount of fines brought to the surface and consequently the texture and density of the finished felted sheet may be varied by adjusting the position of the tamping apparatus ll longitudinal with respect to the suction boxes and the pond from which the sheet is felted as well as by adjusting the stroke of the tampers vertically with respect to the thickness of the sheet being formed. Itis preferred to actuate the tampers at that portion of the travel of the felted sheet which is moist or even submerged underneath the level of the pond. When the sheet is tamped in a moist or wet condition, the lumps are more easily removed, as indicated in Figure 4 and also a finer textured surface is had than if the sheet is tamped dry.

It is not, however, necessary that the tamper be used in conjunction with the skimming device or the skimming device in conjunction with the tamper. Each may be used separately or in conjunction with the other depending upon the type of finished surface which is desired. Referring tamping'a felted fiber sheet tolform a homo-- geneous sheet threughout and a fine textured surface thereon and/or a novel method, in'conjunction with the method of tamping, of skim;

ming the foam and bringing about dissipation of foam formed on the pond of the F0 rdrinier machine so that the resulting finishe felted fiber sheet or board is not deleteriously affected by a deposit of foam on the surface of the sheet as it is being formed. Also there has been disclosed a novel method tamping the felted fiber sheet as it is'being felted for further finishing the surface of the felted sheet in conjunction with the usual agitator found on a Fourdrinier machine.

While the method and construction above described exemplifies-a preferred form of the invention, it will be obvious to those skilled in the art that various modifications of the method are possible without departing from the spirit and scope of the invention as defined in the following claims. a a

What is claimed is:

1. A method of forminga felted board having a smooth and finely fibrous surfaceon a board making machine having a head box, an upwardly inclined felting wire having its lower end passing over a breast roll and between the head assaeas v box and the breast roll a machine stock pond extending forward and over the breast roll and the lower end of the wire to form a wire pond;

comprising the step in connection with the felting of, board on the inclined-wire, of skimming foam and floating material from the surface of the wire pond, returning the so skimmed material to the surface of the machine pond, there by mechanical agitation breaking down foam in the skimmed material and redistributing the solids thereof throughout the fluid stock in the machine pond, felting a sheet from the foam freed stock, and finally tamping the surface of the felted sheet while on the inclined portion of the formi wire. s a p 2. A method of forming a felted board having a smooth and finely fibrous surface on a board making machine having a head box, an upwardly inclined felting wire having its lower end passing over a breast roll and between the head box and the breast roll a machine stock pond extending forward and over the breast roll'and the lo wer end of the wire to form a wire pond; comprising the step in connection with the felting of'board on the inclined wire, of skimming floating material from the surface of the wire pond; returning the so skimmed material to the surface of the machine pond, there .breaking down foam in the skimmed material, redistributing the solids there.-.

of throughout the fluid stock in the machine pond, felting in sheet form, from the wire pond on the inclined wire, the solids of the fluid stock fed thereto from the machine pond and tamping the surface of the felted'sheet while clined portion of the forming wire.

" cam. G. MUENCH.

onathe in- 

